Finished high performance and industrial lubricants consist of two main components. The first and major component is the lubricating base oil. The second is the performance enhancing additives. The additive component is required to assure that the finished composition meets specifications set by government agencies, equipment manufacturers and other organizations. For example, many commercial lubricating compositions have specifications for pour point which is a measure of the temperature at which a sample of the lubricating composition will begin to flow under carefully controlled test conditions such as specified by the American Society for Testing Materials (ASTM).
Pour point depressants are additives known in the art and typically include polymethacrylates, polyacrylates, polyacrylamides, vinylcarboxylate polymers, terpolymers of dialkylfumarates, vinyl esters of fatty acids and ethylene-vinyl acetate copolymers to mention a few. Because of their polymeric nature, these pour point depressants are subject to shearing during their use, thereby impacting the useful life of the lubricating compositions containing them.
Experience has taught that the overall effect of additives may depend not only on the nature and concentration of the additives, but also on the nature of the oil as well. The invention disclosed herein lends support to the observation that the base oil of a lubricant formulation may have an influence on additive performance, especially on pour point depressant performance.